Malaria afflicts 300-500 million people globally and 2-3 minutes die every year. More than a million children die in Africa. The problem is also serious in South East Asia followed by the Indian subcontinent and South America, where economic loss due to morbidity and loss of man-hours is high. The two major parasite species causing malaria are Plasmodium falciparum and Plasmodium vivax, although P. ovale and P. malariae are also involved, but to a minor extent. The P. falciparum parasite causes the most severe form of malaria and is responsible for the majority of cases resulting in death. The other three species, P. vivax, P. ovale and P. malariae, causes milder forms of malaria that are rarely fatal.
Prevention and proper use of treatment is very important in order to constrain malaria infections. The principles of antimalarial treatment policy rely on reducing morbidity and mortality, restricting the transmission of the malaria, reducing the parasites reservoir in the human; and avoiding the appearance and spread of drug resistance (World Malaria Report 2013). The antimalarial treatment should begin right away once the symptoms appear and the infection is confirmed. The type of treatment depends on the severity of the disease, the infecting Plasmodium spp., and the geographical area where the infection takes place (taking in consideration the drug resistance reported in the region). In addition, the treatment differs due to the patient's status including age, weight, other illness and pregnancy, all of these must be taken into account since they may influence treatment to be applied.
Resistance to antimalarial drug is one of the highest problem to control and eradicate malaria. According to “The World Malaria Report 2013, it is extremely important to monitor the drug resistance in order to develop treatment policy and early detection of shift patterns of resistance. Several factors contribute to the development of the drug resistance, for example poor treatment practices, inadequate patient adherence to prescribed antimalarial regimens, and the widespread availability of artemisinin-based monotherapies and substandard forms of antimalarial medicines”
Chloroquine, Sulfadoxine-Pyrimethamine, Mefloquine, Atovaquone-Proguanil, Quinine, Doxycycline and Artemisinin derivatives are drugs commonly used for treating malaria. P. vivax infection is treatable by antimalarial drugs, but the P. falciparum parasites are resistant to the first line and second line antimalarial drugs. The first line of treatment for P. falciparum includes artemisinin-based combination therapy (ACT) to improve the method of treatment and overcome resistance to single drug component (Kokwaro, 2009; World Malaria Report 2013). Combination therapy comprises the use of two or more antimalarials with different mechanisms of action and their objective is to eliminate the infection and prevent the development of drug resistance (Guidelines for the treatment of malaria, 2010). Currently, five ACTs are recommended by World Health Organization (WHO), these include: artemether plus lumefantrine, artesunate plus amodiaquine, artesunate plus mefloquine, artesunate plus sulfadoxine-pyrimethamine, and dihydroartemisinin plus piperaquine (Guidelines for the treatment of malaria, 2010). Severe malaria is an acute infection with high complications, signs of organ dysfunction and high level of parasitemia. Artesunate is the treatment of severe malaria infections in children and adults (Sinclair et al., 2012) followed with a complete course of ACT (Guidelines for the treatment of malaria, 2010). According to the Guidelines for the treatment of malaria 2010, two classes of antimalarial are indicated to treat severe malaria including: the cinchona alkaloids (quinine and quinidine) and the artemisinin derivatives (artesunate, artemether and artemotil). Recently, ART resistance was reported in Thailand (Phyo et al., 2012) and in Northern Cambodia, Vietnam, and Eastern Myanmar (Ashley et al., 2014). ART monotherapy is not recommended due to the reported recrudescence—appearance of parasites after clearance was accomplished during drug treatment—(White 1998) and the chance of selecting resistant parasites as reported in South East Asia (Noedl et al., 2008; Noedl et al., 2009; Dondorp et al., 2009). The WHO stopped the use of artemisinin-based monotherapies in order to help in restraining the resistance.
From the above, there is an urgent need to develop novel antimalarial drug that has a potential to cure the disease, prevent infection and block the transmission. Further there is need of the drug that could destroy drug resistant malaria parasites.